In 1981, Mr. Theodore W. Selby developed the now well-known Scanning Brookfield Technique for determining viscosity values of fluid samples to especially include non-Newtonian liquids. This technique, licensed to the Tannas Co., Midland, Mich., is used in ASTM D 5133, incorporated herein by reference as its 1990 version.
Since then, rotating viscometers have been employed in this and other techniques, among which viscometers may be mentioned those available commercially from the Tannas Co. the former "Scanning Brookfield Plus Eight", "Scanning Brookfield Plus Four" and "Scanning Brookfield Plus Two" models. However, these and other Brookfield viscometers have had some vexing drawbacks of long standing duration.
For example, to obtain reliable results and protect both test sample integrity and components of the viscometer, such sensitive rotating viscometer instrumentation requires a dry gas blanket over the test fluid residing in the viscometer stator component, which is immersed in a bath of temperature regulating liquid such as, for example, methanol. See e.g., Deysarkar et al., U.S. Pat. No. 4,648,263, incorporated herein by reference. To provide dry gas, supply lines such as of TYGON tubing were set up between regulators and viscometer head supporting apparatus. Such tubing, although serving a necessary purpose, was susceptible to crimping, kinking, breaking or becoming disconnected by operator accident, thus impairing the supply of dry gas for the blanket. Moreover, tubing could come into contact with solvents spilled on the heavy-viscometer-head-supporting and bath-protecting housing top, thus becoming susceptible to deterioration therefrom, plus becoming a vehicle for the undesirable transmission of the solvents to personnel operating the instrument or to other locales. Also, such an arrangement was unsightly.
In addition, controls were frequently placed on the top of the housing, engendering increased possibilities of contact with solvents from not only dry air supply lines but also power and data transmission lines, as generally outlined above, thus providing problems from deterioration of lines and from operator-solvent or other contact as could so follow. Also, control panels, if any were present on the instrument such as found in some labs on the rear of the larger, floor models, were provided at awkward heights, and inadequately provided for effective control and monitoring of set-up and test operations.
Furthermore, as understood at the time to be the most efficient arrangement of components, viscometer heads were lined up in straight rows, with instruments having multiple rows of heads having their heads lined up in columns at right angles to the front row of heads. A bath stirring motor was placed to the side of the row(s) of heads. The bath tub was made with a rectangular or square top profile to correspond thereto. Such an arrangement, however, was not without its problems. Operator access to the heads was constrained and could be frustrating as it was difficult to see readings on the front face of the viscometer heads in the rear row, plus difficult to service the front row dry gas supply lines and couplings, and power and data transmission lines and couplings, which couplings are typically in the rear of head support devices and heads, in addition to those for the rear row of heads.
In addition to solutions to problems such as set forth above and otherwise present in the art, increased efficiency and lowered cost of operation are always sought after. What is needed accordingly is rotating viscometer instrumentation which ameliorates or solves such problems and advances the art. A prime goal is the easy and effective use thereof, to especially include, by even inexperienced operators.